The invention relates to a device for cyclically dispensing miniature elements and, more particularly, to a mechanical arrangement therefor affording an accurate, highspeed, and economical dispensing operation. The inventor's employer, Wes-Tech, Inc., an Illinois corporation, shall have a non-exclusive, non-transferable shop-right to make the invention for its own use and incorporate the invention in products sold by Wes-Tech.
There is a need in the assembly of miniature devices or components, such as microswitches, to cyclically dispense miniature parts into or onto corresponding unfinished product portions being passed along an assembly line conveyor belt. Typical present practice has been to utilize a vacuum air pressure operated system to dispense individual miniature parts into corresponding assembly pieces being passed in seriatim on a conveyor line. One such air pressure arrangement, manufactured by Manan Manufacturing Company, Inc., of Skokie, Ill., comprises a supply chamber filled with miniature elements to be loaded which is pressurized such that the elements are agitated. A rotating pick-up arm is formed with a pick-up finger portion connected to a vacuum. The arm first aligns itself with the supply chamber and then inserts the pick-up finger portion into the chamber for retrieval of one element from the chamber. When the finger obtains an element, the arm is then removed from the chamber and indexed over a conveyor line, whereupon vacuum pressure is released and the element is deposited into an unfinished machine part. The system is arranged so that three supply chambers are used and the rotating member is formed with four arms spaced 90.degree. from one another, so that, for every 90.degree. of indexing of the arm assembly, three of the arms contain elements and the remaining arm deposits an element into the corresponding machine part. This type of air pressure operated dispensing arrangement has a relatively high error rate, being approximately 90% consistent at loading, due to the random nature of retrieving elements from the supply chambers onto the pick-up arms. In addition, as in the case of all air pressure operated dispensing mechanisms, the system is relatively expensive to operate because of the quantity of shop air involved and has a relatively high production cost as a result of the many parts.
The present invention is directed to an essentially mechanical arrangement for dispensing miniature elements. The inventive system is relatively compact and inexpensive to operate. In addition, the mechanical dispensing arrangement is nearly 100% reliable.